Medically Reviewed by
Jason Crawford

Article Last Updated on December 24, 2022

So, you’ve been surprised with an announcement for a mandatory drug test at work only a week beforehand and now you’re wondering what you’re going to do about it.

Mandatory drug testing is a nuisance, to say the least, and can put responsible cannabis users under a lot of strain. However, most job sectors require not only random drug testing, but also pre-employment screening as part of the job application. Even though hearing about surprise drug testing isn’t music to the ears, it’s just something you’ll have to do.

If you have a week to prepare for your drug test, then you have to gear up and pull up the big guns. Detoxing from weed in this timeframe is difficult, but not impossible. The first step is to stop using weed altogether. The next step is to learn what you can do to speed up this process, which is what we cover in this article.

What You Should Know About Cannabis Consumption and Drug Testing

To know how to beat the system, you have to know the rules, so knowing a little bit about how drug testing works can give you a head start.

The presence of drugs in the body can be detected by using four main types of drug tests: blood test, saliva test, hair follicle test, and urine test, which is the most commonly used one in the workplace environment.

Urine drug testing, also called urinalysis, is a non-invasive and reasonably accurate method for drug screening where they check your urine sample for drugs. Standard tests are designed to detect the presence of various substances, such as:

  • Cannabis
  • Amphetamines
  • Cocaine
  • Opiates
  • Phencyclidine

The urine is usually tested once, and if there are any positive results, they do confirmatory testing using a different method in order to rule out false positives.

Urine tests have different thresholds at which the presence of a certain drug can be detected. For the marijuana drug test, the threshold is 50 ng/ml (nanograms per milliliter). If the presence of THC in your urine sample is at or above this level, it will be detected and you’ll test positive for weed.

In order to avoid getting positive test results, you have to go through a detoxification process to lower the concentration of THC in the body so it won’t show up on the drug test.

What Do Urine Drug Tests Look For?

You may think that drug tests detect the presence of THC (tetrahydrocannabinol), the psychoactive cannabinoid that gets you high, but this is not the case. In fact, drug tests look for THC byproducts, also called THC metabolites. Let us explain.

Your liver starts to degrade THC not too long after you ingest marijuana. As THC degrades, it leaves numerous byproducts behind that remain in your body for much longer than THC. The THC metabolites bind to the fat cells in your body because they are fat-soluble, and this enables them to stay longer in the body.

The THC metabolite that standard urinalysis can detect is THC-COOH. It gets gradually released through urine, which is why it remains detectable long after the effects of the high have passed.

How Long Does THC Stay Detectable in the Body?

How long THC will remain detectable depends on many different factors:

  • Frequency of cannabis use – occasional users will have less THC accumulated in their bodies compared to heavy users;
  • The potency of the strain – cannabis strains that have higher levels of THC will produce more THC metabolites;
  • Body fat – it is believed that since THC byproducts bind to fat cells, people with a higher body fat content can store them for longer;
  • Metabolism – everyone is different, so the detox process and how your body processes THC will vary according to how your individual metabolism works.

Can You Do a Quick Detox to Flush THC Out of Your System?

The half-life of THC metabolites for infrequent users is less than 2 days after consumption, while for standard and/or heavy users, it can be 5-13 days depending on the frequency. This means that 50% of THC will get eliminated in these timeframes.

Detoxing from THC is not a complicated process, but it does take time. Therefore, a complete detox in a short span of time would be very difficult to achieve. If you only have about one week, then the goal should be to eliminate as much of the THC metabolites as possible, in order to get their concentration below detection levels.

What You Can Do

As THC metabolites are fat-soluble, drinking water alone will not be enough. Yes, it will help to flush out some toxins and it’s generally good for you, but just downing plenty of water for the whole week will be a waste of time. Below are some of the ways people do to detox their bodies of THC. Please note that these are purely for informational purposes only as we don’t recommend cheating drug tests and beating the system.

  1. Drink Water

Instead, drink water as you normally would, but up the intake on the day you test. However, be careful to not overdo it because diluting your urine too much would be suspicious. You need to dilute it just enough to lower the chances of THC detection. 

  1. Add Color and Creatinine Back

However, diluted urine lacks color and creatinine, which is a natural byproduct of your body. In order to make up for them, you’d have to take creatine supplements on the day you test, as well as B vitamins to add some color.

  1. Use a Diuretic

Some people recommend using diuretics such as cranberry juice to make you pee more frequently, but you need to be careful with cranberry juice as it can turn your urine pink, so it’s not recommended to consume it on the day of your urine test.

  1. Exercise

Working out is also recommended as sweating stimulates the fat cells to start releasing trapped THC metabolites faster. Doing cardio exercises or even going to the sauna to sweat it out are both thought to help with the faster elimination of THC. However, please note that as exercise increases the rate at which THC is released, so you’d have to stop exercising at least 24 hours prior to the drug test.

Enter Detox Products

Detox products, such as detox drinks and detox kits, are a temporary solution to help you pass a drug test, and some users claim they have helped. Basically, they are supposed to do all the work for you – dilution and adding color back into the urine. They contain different substances such as creatine, niacin, and natural substances (burdock, milk thistle, green tea, etc) in pre-measured ratios to help you get clean urine.

If you decide to use a detox product, make sure you buy from a reputable manufacturer and do your research beforehand to stay on the safe side, as doing detoxification in a week can be intense for the body.

Bottom Line – It’s Tough, But You Can Do It

Yes, detoxing from weed if you’re a heavy user is tough, but it’s possible to get the THC levels in your body at least below detectable levels. If you’re an occasional user or you have an odd joint here and there, it should be even easier. The last tip we can give you is to use a home THC test kit to see where you are before your actual test. Finally, if you want to do a full detox or take a tolerance break, just wait until after your drug test and do it without stress.

A passionate advocate for the benefits of cannabis. Fraser Horton, who has a background in botany and a strong love of nature, has spent years researching how cannabis affects the body and mind. He established Leaf Nation in 2020, where he has devoted himself to educating people about the legalisation of marijuana and its safe and responsible use. Fraser is committed to highlighting cannabis’ potential for improving wellness and working to dispel the stigma associated with its use.


The information presented on this page is provided as a public service to aid in education and is derived from sources believed to be reliable. Readers are responsible for making their own assessment of the topics discussed here. In no event shall Leaf Nation be held reliable for any injury, loss or damage that could happen if using or abusing drugs.